Mullion assembly

ABSTRACT

A mullion assembly ( 13 ) for a refrigerated cabinet ( 10 ) has an extruded metal post ( 14 ) as its main structural member. A flexible cover strip ( 15 ) is clipped on to the front face of the post ( 14 ), and forms the surface against which the doors of the cabinet seal when closed. One or more magnetic strips ( 16 ) are located between the post ( 14 ) and the cover strip ( 15 ) for magnetic interaction with associated magnetic strips in respective doors. An apertured plate ( 18 ) may be fitted to the rear of the post ( 14 ). A light ( 20 ) is suitably mounted to the rear plate ( 18 ). End caps ( 23 ) may also be fitted to the top and bottom of the post ( 14 ).

[0001] This invention relates to an improved mullion assembly. Inparticular, the invention is directed to a more thermally efficientmullion for a door mounting frame of a refrigerated cabinet, such as acommercial refrigerator or freezer.

BACKGROUND ART

[0002] Refrigerated display cabinets, such as commercial refrigeratorsand freezers found in supermarkets and the like, generally comprise aplurality of insulated glass doors pivotally mounted on a door mountingframe. The door mounting frame includes one or more mullions that extendvertically between the top and bottom perimeters of the frame to providerigidity for the frame, and a sealing surface against which the swingingsides of the doors abut when closed.

[0003] Since a mullion provides rigidity to the door frame, and as itmust be able to withstand slamming of the doors, it is normally in theform of a strong metal structural frame member. Typically, the framemember is an aluminium extrusion. Aluminium frame members are not onlyhighly heat conductive, but also non-magnetic. A steel sealing plate isnormally fixed to the front of the mullion to provide a magneticallyattractive sealing surface against which a door-mounted magnetic gasketcan seal.

[0004] The steel sealing plate normally extends across the width of themullion. Thus, the vertical side edges of the sealing plate extend intothe refrigerated space within the cabinet. The centre portion of thesealing plate is exposed to ambient air in the gap between adjacentdoors. Since the sealing plate is a relatively good heat conductor, thecentre portion of the sealing plate can be cooled to below the dew pointtemperature of the ambient air, resulting in the formation ofcondensation and/or frost on the surface of the sealing plate. Thispromotes the growth of mould, and rusting. It has therefore been thepractice to electrically heat the sealing plate to maintain it above thedew point temperature of the ambient air, but such electrical heatingincreases the operating cost of the unit.

[0005] Various arrangements of insulating and conductive components havebeen used in mullion assemblies in order to overcome the abovementionedproblem. Examples of mullion assemblies using insulating plasticcomponents can be found in U.S. Pat. Nos. 4,330,310, 4,852,303,4,941,289 and 5,035,085, for example.

[0006] However, due to the need to provide a magnetically attractivesealing surface on the mullion, the known mullion assemblies still use ametal plate along their front face. Although the use of other plasticcomponents and insulation in the mullion assembly, assists inmaintaining the sealing plate above the dew point, it has been foundthat the sealing plate will still fall below the due point temperaturefrom time to time, or in certain conditions.

[0007] It is an object of this invention to provide an improved mullionassembly for a refrigerated cabinet which overcomes or ameliorates theabove described problem, or which at least provides the consumer with auseful choice.

SUMMARY OF THE INVENTION

[0008] In one broad form, this invention provides a mullion assembly fora door frame of a refrigerated cabinet, the mullion assembly comprising

[0009] a post member,

[0010] a vertical cover strip fitted along the front of the post memberand forming the front face of the mullion against which a door of thecabinet may seal, the cover strip being made of a material of lowthermal conductivity, and

[0011] at least one magnetically attractive member located between thepost member and the cover strip for magnetic interaction with anassociated magnetic strip on the door.

[0012] Preferably, the cover strip is made of thermally insulatingplastics material. PVC or any other suitable plastics material may beused.

[0013] Since the cover strip is made of insulating material, thermalconductivity is reduced and the risk of condensation is largelyeliminated at normal operating temperatures of the refrigerated cabinet.

[0014] Typically, the cover strip is a flexible clip-on strip which isremovably attached to the post member.

[0015] The magnetically attractive member may be a steel strip.Preferably however, the magnetically attractive member is a magneticstrip which provides stronger attraction to the magnetic strip in thedoor gasket. Normally, two spaced parallel magnetic strips are locatedalong the front of the post member behind the cover strip, for magneticinteraction with associated magnetic strips in gaskets of the respectivedoors which close against the mullion. As the cover strip is removablyattached the post member, the magnetic strips can be easily accessed.

[0016] Heating wires may also be located between the post member and theinsulating cover strip, if desired.

[0017] The post member is typically a C-shaped aluminium extrusion orthe like. A rear plate may be fitted to the post member, spaced from thefront portion thereof to form a cavity. This cavity may be filled withinsulation, such as expanded foam.

[0018] In some refrigerated cabinets, a fluorescent light or other striplighting is provided at the back of the mullion for illuminating thecontents of the cabinet. If mullion-mounted lighting is provided, therear plate is preferably perforated or otherwise foraminous, and noinsulating material is provided in the cavity between the rear plate andthe front portion of the post member. In this manner, heat can travelfrom the light towards the front of the mullion, and used to heat thefront face of the post and the cover strip.

[0019] Preferably, the ends of the mullion assembly slide or clip intoend brackets fitted to the cabinet. The end mounting brackets not onlyprovide a neat flush appearance, but also hide the entry points ofheating wires and power wires for the lighting.

[0020] In order that the invention may be more fully understood and putinto practice, a preferred embodiment thereof will now be described withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a perspective view of a refrigerated cabinet having amullion assembly,

[0022]FIG. 2 is a fragmentary exploded perspective view of the mullionassembly of the refrigerated cabinet of FIG. 1,

[0023]FIG. 3 is a schematic section elevation of the mullion assembly ofFIG. 1,

[0024]FIG. 3a is an enlarged fragmentary sectional elevation of themullion assembly,

[0025]FIG. 4 is a sectional plan view of the front portion of therefrigerated cabinet of FIG. 1 having a mullion assembly with lighting,

[0026]FIG. 5 is a sectional plan view of the front portion of therefrigerated cabinet having a mullion without lighting.

DESCRIPTION OF PREFERRED EMBODIMENT

[0027] As shown in FIG. 1, a refrigerated cabinet 10, suitable for useas a commercial refrigerator or freezer, has frame 10A on which a pairof glass doors 11, 12 are mounted. The doors 11, 12 close against acentral mullion assembly 13 mounted in the frame 10A.

[0028] The mullion assembly 13 is shown in more detail in FIG. 2. Themain structural component of the mullion assembly 13 is a post member 14which is typically an aluminium extrusion.

[0029] A plastic cover strip 15 is snap-fitted to the front of the post.The cover strip is made from a suitable plastics material which isthermally insulating, i.e. of low thermal conductivity.Polyvinylchloride (PVC) may be used for the cover strip. C-shaped edgesintegrally moulded on the plastic strip 15 clip onto cooperatingC-shaped formations extruded with the post extrusion 14.

[0030] The plastic strip 15 is detachably affixed to the front of thepost 17. The engagement of the edges of the cover strip 15 with the postextrusion 14 is made secure enough such that a tool is required forremoval of the cover strip. This deters unauthorised removal of thecover strip 15. However, although a tool is required, a simple tool suchas a screw driver is sufficient to lever the edges of the cover strip 15out of engagement with the post extrusion 14.

[0031] The plastic strip is of low thermal conductivity and hence thecentre thereof between the doors is not cooled to below dew pointtemperature.

[0032] A pair of magnetically attractive strips 16 are located betweenthe post 14 and the cover strip 15. The strips 16 are suitably locatedin respective longitudinal recesses formed in the post extrusion. Thestrips 16 may be metal strips to which magnetic strips in the gaskets ofdoors 11, 12 are attracted when the doors are closed against the mullionassembly 13. Preferably, the strips 16 are magnet strips to strengthenthe magnetic attraction with the magnetic strips in the door-mountedgaskets.

[0033] If desired, heating wires can be provided between the post 14 andthe cover strip 15. Groove formations 17 are extruded with the post 14to provide recesses in which such heating wires can be located.

[0034] A rear plate 18 is provided between the free edges of theC-shaped post extrusion 14. The rear plate 18 is spaced from the frontportion of the post 14, and the intermediate space may be filled withinsulating material (not shown) such as expanded foam.

[0035] In many applications, a fluorescent light will be mounted to theback of the mullion 13. Typically, a fluorescent light tube 20 is fittedto mounting brackets 19 fixed to the rear plate 18. A transparent ortranslucent light cover 21 is fitted to the post 19. (For this purpose,barb-shaped longitudinal edges on the light cover 21 locate in recessformations 14A extruded with the post 14 for this purpose).

[0036] If a light is provided at the back of the mullion assembly,perforations 22 are provided in the rear plate 18. The perforations 22allow heat from the light 20 to pass forwardly to the front of the postextrusion 14 by convention and radiation. (No insulating material isprovided in the post, thereby avoiding problems arising from foam leaksduring the foaming process).

[0037] It has been found that in refrigerator applications, the heatfrom the light 20 is sufficient to maintain the front of the postextrusion 14, and the cover strip 15, above dew point temperature toeliminate condensation. For freezer applications, i.e. temperatures from0° C. to −25° C., a single resistance style heater wire located in oneor both of the recesses 17 is sufficient to eliminate condensation onthe cover strip 15. The heater wires may also be used in environments ofextreme humidity.

[0038] Plastic end shoes 23 are provided at the top and bottom of themullion assembly 13 to ensure positive placement and fastening of themullion assembly. The end shoes are fixed to the top and bottom of thecabinet frame. The plastic mounting brackets of the end shoes 23 simplyslide onto and/or clip onto the ends of the mullion assembly, andprovide a neat flush appearance to the whole mullion portion of the doorframe. An aperture 24 in the end shoe 23 allows passage of the heatingwires as well as the power wires to the light mounts 19, yet concealsthe wire entry points through the cabinet. Thus, the heating and lightwires are completely concealed within the mullion and cabinet.

[0039] The foregoing describes only one embodiment of the invention, andmodifications which are obvious to those skilled in the art may be madethereto without departing from the scope of the invention as defined inthe following claims. For example, although the invention has beendescribed with particular reference to a post-type mullion assembly, theinvention is also applicable, with suitable modification, to a mullionwall.

1. A mullion assembly for a door frame of a refrigerated cabinet, themullion assembly comprising a post member, a vertical cover strip fittedalong the front of the post member and forming the front face of themullion against which a door of the cabinet may seal, the cover stripbeing made of a material of low thermal conductivity, and at least onemagnetically attractive member located between the post member and thecover strip for magnetic interaction with an associated magnetic stripon the door.
 2. A mullion assembly as claimed in claim 1 , wherein thecover strip is a flexible clip-on strip made of plastics material whichis removably attached to the post member.
 3. A mullion assembly asclaimed in claim 1 or 2 , wherein the magnetically attractive member isa magnetic strip extending longitudinally along the post member.
 4. Amullion assembly as claimed in claim 1 or 2 , wherein said at least onemagnetically attractive member comprises two spaced parallel magneticstrips extending longitudinally along the post member, for magneticinteraction with an associated magnetic strip of a respective door ofthe cabinet.
 5. A mullion assembly as claimed in any preceding claim,further comprising at least one heating wire located between the postmember and the cover strip.
 6. A mullion assembly as claimed in anypreceding claim, wherein the post member is a generally C-shaped metalextrusion.
 7. A mullion assembly as claimed in claim 6 , furthercomprising a plate member fitted to the rear of the post member, andspaced from the front of the post member to form a cavity between theplate member and the front of the post member.
 8. A mullion assembly asclaimed in claim 7 , wherein the cavity is filled with a thermallyinsulating material.
 9. A mullion assembly as claimed in claim 7 ,further comprising an electrical light mounted to the rear of the platemember, the plate member having apertures therein.
 10. A mullionassembly as claimed in any preceding claim, further comprising endbrackets fitted to the ends of the post member, the end brackets havingapertures therein for passage of electrical wiring.
 11. A refrigeratedcabinet having a door frame on which at least two doors are mounted, thedoor frame having a mullion assembly against which the two doors close,the mullion assembly comprising a post member having a front side, avertical cover strip fitted along the front side of the post member, thecover strip being made of a plastics material and forming the front faceof the mullion against which the doors of the cabinet may seal, and apair of magnetically attractive strips located between the post memberand the cover strip for magnetic interaction with an associated magneticstrip on a respective door.
 12. A refrigerated cabinet having a mullionassembly comprising a post member having a front side, a vertical coverstrip removably fitted to the front side of the post member, the coverstrip being formed of a flexible plastics material, the cover stripforming the front face of the mullion assembly against which a door ofthe cabinet may seal, at least one magnetically attractive memberlocated between the post member and the cover strip for magneticinteraction with an associated magnetic strip on the door, and anelongate plate member fitted to the rear of the post member, and spacedfrom the front side thereof so as to form a cavity between the platemember and the front side of the post member.
 13. A mullion assemblysubstantially as hereinbefore described with reference to theaccompanying drawings.